Although a hydraulic pressure is supplied to a transmission of a motor vehicle by a hydraulic pump, in a motor vehicle which performs so-called idle reduction which shuts down an engine when the motor vehicle stops from the viewpoint of saving energy, an electrically operated hydraulic pump is used to ensure the supply of a hydraulic pressure to the transmission even during performing the idle reduction.
An electrically operated hydraulic pump for a transmission of a motor vehicle is installed in a limited space in a vehicle body. Therefore, there is a need for an electrically operated hydraulic pump to reduce the size thereof and also to reduce the weight and production costs thereof. With a view to meeting these requirements, an electric pump unit is proposed, in which a pump, a pump driving electric motor and a controller for the electric motor is incorporated in a common unit housing (refer to Patent Document 1, for example).